[VACList] Storing opened caulking tubes?

[John Leggett <pklhead2@xxxxxxxxx>]

I'm curious if anyone has come up with a way to store
opened tubes of Vulkem, without them hardening up. 
There always seems to be that one little sealing job
that demands opening that $7 tube.  I've tried
plugging the end, taping over the plug, putting them
in ziplock bags... but the delivery end always plugs. 
With my new heavy-duty caulking gun, the half-used
tube I tried to re-use this weekend ended up splitting
the casing in the middle, rather than exiting the
nozzle.  I was able to salvage the goo in the middle
and load some small syringes for my purposes, but as
always that stuff ends up getting on everything.
Any better ideas from you veterans?
John Leggett
1968 Safari 22
WBCCI 1154